A variety of products may involve three phase motor control applications, for example for position control and/or low speed applications.
Home appliances such as washing machines, dryers, refrigerators, industrial and home automation, the automotive sector and medical devices may be exemplary of such products.
Sensorless motor control is increasingly becoming a standard solution for applications where cost reduction and increased robustness (“sturdiness”) may represent significant factors.
Control at zero or very low speed (“zero-speed control”) may represent a technical issue in sensorless motor control, for example in providing position control, speed reversal, maximum torque at the startup, full torque at zero speed.
Certain implementations may address this issue for example by exploiting:                motor anisotropy in direct and quadrature axis,        resistance/inductance variation due iron saturation effects,        mechanical motor asymmetry in the iron, or        permanent magnet asymmetry.        
While effective, these and other methods may be limited by factors such as:                having to rely on specific motor type (salience), construction (iron or magnet asymmetry, neutral point availability), or other effects (iron saturation);        the need of having salience on rotor with difference between direct and indirect axes, or a stator winding in star connection with an accessible neutral point;        cost of position sensors; and        limited speed range and limited applicability to different motor types.        
There is a need in the art to overcome the critical issues mentioned in the foregoing.